MLA

Marinetti, F. T., 1876-1944. Anton Giulio Bragaglia. “Sport e teatro di massa.” No source, [1935-6]. [7774-1]-[7777-1]. box 98, slide 34-37. 1935 or 1936. https://collections.library.yale.edu/catalog/10661207.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 98, slide 34-37"])(1935 or 1936)[Anton Giulio Bragaglia. “Sport e teatro di massa.” No source, [1935-6]. [7774-1]-[7777-1]]. https://collections.library.yale.edu/catalog/10661207.